about paeoniarockii Growth and development characteristics

 (1) Long life span paeoniarockii is a long-lived tree species. In its life process, from seed germination to gradual aging, it undergoes a series of staged age changes. In the first three years, the seedlings grow slowly, mainly root growth, and the height of the aboveground part is less than 15 cm. After the fourth year, the growth accelerates, and the plant height can reach 40-60 cm in the fifth year. Some individuals begin to bloom after 4 years. The adult stage is strong and blooms luxuriantly, which is the best viewing period. This stage lasts about 60-100 years or longer depending on management conditions, and then enters the old age stage, the growth declines, and needs to be renewed and rejuvenated.

In the annual cycle, the paeoniarockii also shows the characteristics of spring branching, summer nap, autumn rooting, and winter dormancy. Due to climatic conditions, its annual growth period is significantly shorter than that of the Central Plains peony. In Gansu, it generally sprouts from late March to early April, blooms from late April to early June, leaves wither from mid-October to early November, and then enters a dormant period.
(2) Tall plants, strong growth potential, and strong resistance
The paeoniarockii plant is tall and has strong growth potential. After the flower buds (mixed buds) on the adult plants germinate, the branches and leaves grow in coordination to ensure the normal development and flowering of the flower buds. The leaves are initially small and curled, and only unfold and rapidly increase when the flower buds enter the wind chime period, reaching the best state after the flowering ends. Before flowering, the leaves mainly grow and develop on their own, often competing with the flower buds for nutrients and growth regulators. After the flowering period, the leaves grow fully, and their photosynthetic products become the main nutrient source for various growth and development processes of the plant.
Before flowering, paeoniarockii branches are in primary growth, that is, elongation growth is the main growth, and after flowering, they are in secondary growth, that is, thickening growth and lignification are the main growth. The growth of new branches of most varieties is better than that of the Central Plains peony, reaching 40~50cm. Because the upper part of the branch without buds dies in winter, its actual length is only about 1/3 of the annual growth.

(3) Short and concentrated flowering period, low degree of variety evolution
After the flower buds sprout, it takes about 50 to 60 days from the appearance of the buds to the flowering. The early and late flowering period is closely related to the spring temperature of the year. Warm or cold spring can advance or delay the flowering period by 7 days or more. The temperature during the flowering period has a more direct impact on the length of the flowering period. High temperature weather can greatly shorten the flowering period. Since changes in altitude affect environmental factors such as temperature, light and humidity, they have a significant impact on the flowering period of peonies. Generally, the flowering period is delayed with increasing altitude. In Lanzhou, Gansu, the peak flowering period in the urban area (1550m) is at the end of April and the beginning of May, the Heping Peony Garden (1750m) in the suburbs is in mid-May, and the Gaolan Mountain (2100m) on the south side is in late May.
The Northwest peony has a short and concentrated flowering period like the Central Plains peony. The group flowering period is generally about 20 days. Its variety evolution is low, and there are few varieties, generally less than 5%.
(4) Well-developed root system
The seedlings of Paeonia purpurogena have obvious taproots, which are typical taproot systems. However, adult plants have large fleshy root systems, and the taproots are no longer obvious. Most of the fleshy roots are 50-80cm long, and a few can reach more than 1m. In loess mountains, they can sometimes reach several meters deep. Vegetative propagation seedlings reestablish a complete root system after 2-3 years, and there is no obvious taproot.

Cultivation and management techniques of Paeonia rockii

 This paper introduces the cultivation technology and maintenance management technology of tree peony, and probes into the promotion and development of tree peony. Chinese tree peony has a long history, has been deeply loved by the majority of working people, treepeony not only flourish in China, development, but also spread to the world.

Chinese tree peony has a long history, has been deeply loved by the majority of working people, tree peony not only flourish in China, development, but also spread to the world. Under the influence of different overseas flower appreciation consciousness and aesthetic concept, different varieties of traditional Chinese tree peony have been gradually formed. In particular, Japan and European and American countries not only introduced many excellent traditional varieties from China, but also cited many precious wild species, and as parents, bred many new varieties.

Although the tree peony is so beautiful and people like her so much, when it comes to maintaining her, some people dare not pay attention to it. The reason is that everyone thinks that although the tree peony is beautiful, it is not easy to maintain, it’s easy to raise her as long as you have some knowledge.

1 the characteristics of tree peony

Peony is a kind of cold-resistant plants, like the Sun but do not like the heat, as long as to maintain adequate sunlight and 24-25 degrees C temperature, you can maintain a strong vitality. And tree peony like sandy soil and soft soil, especially avoid sticky and hard soil, so to ensure that the soil is soft peony growth factors. At the same time, the best time to plant tree peonies is autumn, should be dry autumn weather, so peonies in this season survival rate can reach 99% , winter is 96% , spring 98% , the worst in summer about 90% .

2 cultivation and maintenance management

2.1

tree Peony is widely used in gardens because of its strong growth and easy cultivation. In order to make the flowers big and colorful and obtain good ornamental results, we should take integrated scientific cultivation and management measures according to the biological characteristics and ecological habits of peony.

2.1.1 site selection. tree Peony likes cool and fears heat. It often grows poorly in areas with an annual average of 15 ° C and above, especially in summer. The optimum temperature for growth was 12 ~ 15 °C. It is advisable to shade the area slightly, in sufficient light can also be normal growth. Sex likes high dry, bogey low wet, the planting place is suitable the terrain is high open, the drainage is good. The root is thick and long fleshy root, when it grows well, the root length can reach more than 1m, so the soil layer is deep, loose and rich sandy loam. Saline-alkali soil, clay and waterlogged depression are not suitable for planting peony, like rotation avoid replanting, peony planted places, after 2-3 years before replanting.

2.1.2 selection of seedlings. (1) the variety is correct. (2) the vigorous growth stems are stout, the buds are full and the thick roots are many. Strong seedlings have strong resistance, high survival rate and rapid growth. (3) the graft site healed well and Ramets retained more roots. (4) no diseases and insect pests.

2.1.3 planting

Planting time: tree peony planting is usually carried out at the same time as the ramets. It can be planted from late September (autumn wind) to mid October. It is not suitable to plant tree peony in spring, because the root system began to move in early spring, bud germination in early March, then shoot spread leaves, now bud flowering, consume a lot of nutrients and water.

Planting method: Dig Pit before planting, diameter 30 ~ 40 cm, depth 40 ~ 50 cm, pit distance 100 cm. When digging a pit, the topsoil is separated from the subsoil so that the topsoil can be backfilled in the lower part of the pit when planting, and mixed with decomposed compost and fertilizer such as bean cake, chicken manure and sesame paste. After the soil and fertilizer are mixed evenly, pile a”Mound” in the pit, then sprinkle a layer of inorganic topsoil on it, distribute the root system of the seedling evenly on the”Mound”, make the root system extend naturally, then fill the soil, fill to half full, for gently lifting seedlings, shaking, so that the soil and root close, with feet, pay attention to the roots and the ground level. Depending on the soil conditions, such as the soil is too dry, 1 week after watering 1 time. When the soil is dry, bury the plants in fine soil. This is beneficial to keep warm over winter and maintain soil temperature, improve survival rate.

2.1.4 conservation management

2.1.4.1 water. (1) first-time seedlings should be fully watered to ensure adequate watering, promote root and soil contact, in order to absorb water and nutrients. (2) the watering time should be regular. When it is hot, it should be done before sunrise or at night when it is cool. When it is cold, it should be done when it is warm. (3) when the spring bud sprouts, it is good for the growth and development of peony to water it once. (4) hot summer weather, more rain, peonies do not need to water, water more root injury, not flowering every year. (5) to control the autumn watering, water will cause autumn hair, and lead to next year flowering difficulties.

2.1.4.2 top dressing. Peony flower large-leaf propagation, growth and development process to consume a lot of water, in order to achieve good cultivation results, timely fertilization is very important. It is usually planted without topdressing and then fertilized 3 times a year. The first time in the spring after the soil thawing, known as”Flower Fertilizer.”. The second time after flowering, called”Bud fertilizer”. The third topdressing is called”Winter fat”.

2.1.4.3 plowing and weeding. Intertillage and weeding are usually combined. Intertillage plays an active role in improving soil aeration and regulating soil moisture. Weeds not only compete with peony for water and nutrients, but also affect ventilation and light transmission, easy to occur diseases and pests. From the spring, it is necessary to follow the”Small, clean” principle of loose soil weeding, especially in July and August, hot rain frequently, weeds breed fast, but also frequently clear.

2.1.4.4 plastic trimming. Shaping and pruning is an important technical operation in tree peony cultivation, which mainly includes drying, budding and picking buds. The aim is to keep the plant in balance, with a moderate amount of branches and an aesthetically balanced posture. To maintain the Dynamic equilibrium of the above-ground and underground parts, remove vegetations and make them ventilated and light-permeable, which is conducive to concentration of nutrients and enable vigorous growth.

The three most common breeding methods of peony

The propagation methods of tree peony can be divided into sexual propagation (sowing) and asexual propagation (grafting, Ramet) .

1. Sow

Because of the large propagation coefficient, sowing is used to breed rootstock and breed new varieties. The cultivation of medicinal peony is mainly propagated by seed.

In the wild state, tree peony mainly propagates its offspring by seeds. After long-term artificial cultivation, peony stamens and pistils degeneration, change into petals, most of the loss of fruit-bearing capacity. Therefore, asexual propagation has become the main propagation method to keep the fine characters of tree peony. According to the observation, the higher the evolution degree of Peony Flower Type (that is, more flower layers, Rise) , the more serious the degeneration of pistil and stamen, the smaller the possibility of fruiting. Only single and semidouble varieties and Fengdan can bear seeds.

Peony seeds are usually collected in late July to early August. The seed coat inside the pod changes from white to blue. Peony species like tender does not like old. Not fully mature peony seeds of its many characteristics are not fixed, not only after planting is easy to germinate, but also easy to produce variation, the formation of new varieties. The mature peony seeds had a low germination rate when they were sown, and some of them did not germinate until next year.

The peony seeds take root after 15-20 days after sowing, then germinate and burrow from late February to early March of the following year, remove the mulch in advance, and water them once every 10-15 days with little rain in some dry areas, thin manure may be applied after April with watering. According to this method, the seedlings can be used for grafting or transplanting after two years of sowing, and after 3-5 years they can blossom successively. However, most of the non-grafted seedlings had white single-layer flowers and few had pink multi-layer flowers.

2. grafting

Grafting is the best method to propagate peony varieties and keep the good varieties and genetic characters. It can propagate quickly and increase the propagation coefficient. The ornamental quality and application value of peony were improved by grafting.

(1) selection of rootstocks

The root of 2-3-year-old seedlings of Paeonia lactiflora or paeonia lactiflora was used as the grafting rootstock, and the seedling with the diameter of 1cm or more was used as the rootstock.

(2) Scion selection

The Scions should be selected from the healthy plants, which are the first-year-old branches with strong sprouting shoots and pith and solid, and the second-year-old branches with strong sprouts and full sprouts, which contain more nutrients, and the second-year-old branches with strong sprouts, good for wound healing and survival. The scions are generally about 6 ~ 10 cm long with robust terminal buds and one or several small lateral buds. The scions should be clipped or jointed and not put in for long.

(3) grafting method

1 grafting: the grafting time of peony is usually from the first ten days of September to the first ten days of October, and the suitable temperature is 15 ~ 28 °C. By:

Dig out the rootstock to clean the soil on the root, put in 500 times isofenphos-methyl and topsin mixture soaked in 15 to 20 minutes, remove and dry the liquid medicine. Cut off the rootstock above the rootstock with the eye of the bud, split it with a sharp blade from the middle, and insert the cut Scion, aligning the cambium (that is, the cortex) ; if the rootstock and scion are not of the same thickness, just align it on one side. Tie with bast from top to bottom, then apply evenly with a thick and moderate paste on the incision, be sure to completely paste the wound. According to the provisions of deep planting, planting depth to the wound and natural ground is appropriate. Then the soil for the ridge, Ridge High to be able to completely bury the degree of Scion, too deep impact on the survival rate, too shallow scion easy to dry. Can not be watered within 20 days, so as not to affect the healing; first ten days of the following March unearthed alive, the general survival rate of more than 80% . After the survival of a number of drought in mid-march after half-monthly watering, watering twice in the water ploughing and weeding once; Phosphate and potassium fertilizers (5 ~ 7 kg per mu) can be applied once in late June, and can be sold or transplanted out of the garden after two years.

2 Bud Grafting: the bud grafting of tree peony is mainly used for changing varieties or cultivating a multi-colored plant. Bud grafting time should be from early May to late June, the operation time should be in 10 ~ 17 hours, at this time the cortex should be separated, adhesive. The axillary buds on the grafted part of the rootstock were removed together with cambium to retain the intact woody bud base, and the buds on the scion were peeled off in the same way and quickly sheathed on the rootstock bud base. Note that the two should coincide with each other, and finally with graft tape tight. The next month, when the bud is considered to have survived, remove the rootstock with tape to remove vegetations. The leaves on the rootstock should be retained to concentrate nutrients on the bud, which is conducive to the formation of full flower buds in the current year, flowering the following year.

3 subcutaneous: the time must be in early September to early October. The wound heals easily when the temperature is 20 ~ 25 °C. The length of the scion is 4 ~ 8 cm, and the flower bud is usually selected, and the two sides of the scion should be cut at 2 ~ 3 cm below the Scion, the long and short sides should be about 3 cm and 1 cm respectively, and the cut should be smooth. The thick lateral branches were selected as rootstock, and a 2-3cm long interface was cut on the side of the smooth upper branches. The scion is inserted into the base of the rootstock notch slightly obliquely, so that the two layers are closely connected and compact; if the thickness is not the same, one side can be aligned. Tie the joint from top to bottom with grafting tape, hemp rope and other materials, then cover the joint and the joint with a plastic bag, tie the plastic bag mouth tightly at a distance of 1 cm from the joint, so as to keep the temperature and moisture, and avoid the infiltration of rain water, improve the survival rate.

3. Ramets

Ramets are also called ramets. Tree peony is a cluster shrub, most varieties of roots often produce adventitious buds and germination branches. There are more than ten branches in a cluster of peony peonies, and there are 3 ~ 5 roots under each branch to supply nutrient and water, and the branches are connected with each other, therefore, in the Ramet reproduction must be aware of the root of the relationship between the interconnection, along its”Texture” natural potential for ramet, must not be arbitrary pull hard cent. In Luoyang, Ramet breeding is usually carried out in early October and not later than the end of November. If the time ramets, peony new root many, the next year vigorous growth, late ramets, its new root less and short, next year germination because of new root less, poor absorption of water and nutrients, seedling growth weakness or even death.

Key points of land arrangement for tree peony planting

Time and choice of land consolidation

Need to be sorted out in August, the soil can be neutral slightly acid and alkali

2. Good drainage measures

Tree peony planting areas try to choose near the river, drainage ditch, higher terrain. According to the terrain block"Field" character cutting, digging around drainage system to prevent water.

III. Good choice of land after the need to turn deep to 40-50 cm, such a strong permeability, suitable for the growth of peony

Use Fertilizer and medicine before deep ploughing

Before the land is plowed deeply, you can sprinkle some organic bacteria fertilizer and chemical fertilizer on the soil (acid and alkali) , you can also use organic fertilizer, you can choose animal dung such as sheep dung, cow dung, you can also use some soybean meal and so on, but must be fermented before you can use, before the use of drugs to do the treatment, the drug is mainly used for sterilization, killing the adult eggs of underground pests. The drugs used include Carbendazim, phoxim, and fosthiazate, which are stirred evenly and then spread evenly over the fields.

Common Pests and Diseases of Peony-

Tree Peony, as China’s unique woody flowers, with thousands of years of natural growth and more than 2000 years of artificial cultivation history, widely loved by the people, often found in the garden or landscape. However, in the process of tree peony cultivation, due to weather, soil and management and other reasons, it is easy to appear disease. The infected plants often show the phenomenon of leaf covered with disease spot or edge withered, branches thin and weak, root rot and disfigurement, if the infected plants are not treated in time, the disease will spread in a large scale, which greatly affects the ornamental value and economic value of the tree peony. Therefore, peony disease control is an important part of the cultivation of peony, today to give you a brief introduction of the six major peony disease control.

01Anthrax

Damage parts: stems, petioles and petals and other plant young tissues

Manifestation: the leaf surface will appear small brown spots, when serious into a round or irregular spots can lead to perforation, the affected young leaves will also show the characteristics of shrinkage, curling. After infection, the stem will appear initially reddish brown oblong spots, then will develop into large irregular spots, the middle will appear inconspicuous light gray, the edge of the spot is reddish brown. Infected stems will bend and eventually fold, and young stems will wither and die in a short period of time. The petal and the flower scale can appear bud wither and the deformity flower and so on question, if the occurrence disease is in the rainy and wet season, the surface also can produce the pink spore pile.

High incidence: the pathogen of anthracnose usually overwintering in the form of hyphae in the diseased plant. Conidia will germinate and spread when the temperature is suitable in the second year.

Methods of prevention and Cure:

1 deep turn the soil of peony cultivation, improve the air permeability of soil and the environment of microorganism growth, ensure the root can stretch to grow, absorb sufficient nutrient.

(2) pruning the whole plant in time, removing dead branches and debris, and burying or incinerating them.

3 spraying 75% Mancozeb or Anthrax Thiram 500 times, once every 15 days, continuously spraying 2-3 times.

02 Powdery mildew

Damage parts: leaves and petioles

Manifestation: the peony leaves will form a layer of white powdery spot in the early stage, and the disease spot will appear on both sides of the petiole and leaf surface in the late stage, accompanied by many small black spots, and gradually expand and develop into a large area of disease spot, it can cause whole leaves and stalks to wither and die.

High-incidence period: generally in the rainy and wet season occurs very serious, too dense plants or poor ventilation can also cause peony powdery mildew.

The control methods were as follows:

(1) proper pruning and shaping could be carried out to improve the ventilation and light permeability of the plants and to remove the infected leaves in time. (2) spraying 20% triadimefon WP and strengthening field management, phosphorus and potassium fertilizer could be applied properly, but the amount of nitrogen fertilizer should be strictly controlled to improve the disease resistance of plants.

3 sulphur mixture could be sprayed before sprout in spring, 80% Mancozeb wettable powder or carbendazim could be sprayed at the onset of disease in growing season, once every 15 days and three times continuously.

03Root rot

Damage: Root

Manifestation: the leaves will turn yellow or reddish, some mesophyll will turn yellow, while the growth of some plants on the ground is weak, serious will lead to leaves and branches withered, the whole plant death, the roots of the diseased plants were found to be rotten and dark brown.

High incidence period: the field environment is humid, water accumulation is serious. In addition, the plants which were not transplanted with soil ball during Ramet transplanting were also susceptible to disease.

Prevention and Cure Method: after the soil is deeply turned, carbofuran can be applied, and carbendazim WP can be sprinkled on the base of peony root, every 10 days, to ensure that the medicine can be deep underground.

04 Leaf spot

Damage parts: leaves and shoots

Manifestation: 15 days after flowering, brown spots appear on the abaxial surface of the leaves, the edge of the color is darker, and then developed into an irregular circular spots, all the spots can be connected into one, leading to leaf wither and fall. Infected stems and stalks produce raised lesions, and pathogens can overwinter in stems, leaves, and soil.

High incidence period: generally in the rainy season onset of serious, in high temperature and humid conditions.

Control methods:

1 cut off the infected branches in time before and after the beginning of winter and burn them to ensure that the pathogen was completely eliminated.

2 Bordeaux mixture and thiophanate-methyl were sprayed 3-4 times before the onset of the disease.

05Botrytis cinerea

Damage parts: young plants and peony flowers, stems and leaves and other parts

Manifestation: cause the tree peony seedling lodging and withering, death. The infected parts give birth to gray mold, brown spot also appears on the stem, peony peony seed will be seriously affected when the peduncles encounter this kind of disease.

High incidence: July-august every year, when the weather is wet.

Control methods:

1 new soil transplanting, old soil can be sprayed with pentachloronitrobenzene wettable powder for disinfection treatment.

2 control planting density, ensure timely drainage after ventilation and light permeability.

3 the infected branches, leaves and buds should be cleaned up in time, and the whole plant should be pulled out and destroyed.

4 Bordeaux mixture and thiophanate-methyl solution can be used to prevent and cure the disease.

05 seedling damping-off disease

Damage parts: stem base and whole plant

Manifestation: in the process of seedling raising and germination, seedling damping-off will lead to hypocotyl and leaf rot. The seedlings were infected by the disease after they were unearthed, and the first damage was to the base of the stem. Canker lesions appeared on the affected parts, then changed from light brown to yellow brown, and spread around the whole stem, seeds that have not sprouted can also be infected when the disease is severe. Usually, seedling damping-off is mainly caused by pathogenic fungi of the genus Phytophthora. The disease can be spread by means of agricultural machinery, transplanting and farm manure.

Control methods:

1 select disease-free new soil, do not use diseased field to raise seedlings, but also choose Mancozeb and metalaxyl medicament, evenly mix and spread on the border.

2 in addition, peony seeds should be disinfected in 50 ° C warm water for 20 min, then diluted with pyrazolium and Mancozeb etc.

Why paeoniarockii (gansu mudan) is more valuable than other tree peony varieties

For tree peonies, China has a long history of cultivation. China is the birthplace of the world's tree peonies. Through continuous development, many precious varieties have been cultivated, and they have a heavy position in the global peonies, in China, tree peonies represent wealth, harmony, peace and health. Each family yard or flowerpot will be planted with a peony tree.

China has a vast region, the special geographical location and climate of the Chinese tree peony and divided into northern tree peony and southern tree peony, the most representative of the northern tree peony is produced in Gansu Paeonia rockii, southern peony is the most representative of Henan, Shandong peony.

Located in the Northwest China, Gansu province is rich in natural resources and is the second most popular tourist destination in Asia, in this barren soil bred out of a tree peony people can not forget the variety of paeoniarockii(gansumudan).

In the 19th century, Joseph F. Rock, a famous botanist, discovered the tree in Gansu province and introduced it to Europe,To now constantly exported from Gansu around the world, the widespread spread of the value of paeoniarockii

so why the value of paeoniarockii (gansumudan) is higher than other treepeony varieties, I will explain from the following aspects

1. Paeonia rockii planting simple, can adapt to a variety of soil, stable flowering

2. Paeonia rockii is the only tree in the world can grow into tree peony, high degree of anti-aging lignification

3. The fragrance of paeoniarockii (gansu mudan )is stronger than that of other tree peonies. The fragrance of one flower is better than that of 100 flowers

Four. Paeonia rockii has strong cold resistance and can overwinter naturally under the environment of -30 degrees without artificial protection

 

TECHNIQUES OF FERTILIZING TREE PEONY

 First, before germination to fertilize before the buds

As we know, peonies are more beautiful and large when they bloom, and they consume more nutrients. In spring, peonies not only have to blossom, but also have branches and leaves, so in spring, the leaves and buds are ready to be fertilized when the flower buds sprout.

Before fertilizing, first water, to ensure a certain amount of moisture, so the peony will be better absorption, and play the due fertilizer effect. At this time, we can use decomposed organic fertilizer, such as decomposed chicken manure, decomposed cake fertilizer, etc. , and try to mix a little compound fertilizer, such fertilizer, all kinds of nutrients are more complete, can meet the needs of peony growth and the coming flowers.

Pay attention to fertilization point and peony should have a certain distance, avoid and root direct contact, as far as possible ring-shaped fertilization, is conducive to uniform absorption of roots everywhere.

In addition, when the bud appears, you can use some phosphate fertilizer, but also leaves sprayed with Monopotassium phosphate, which will make the peony flowers bloom more colorful, bloom longer, wait until the flower color, exposed, do not fertilize.

Two, after using flower fertilizer

People pay attention to the fertilizer before flowering, after flowering, they often put the peony flower aside and no longer manage it. In fact, this is a misunderstanding. After flowering, the management and fertilization of the peony flower are more important. After the peony blossom, will consume a lot of nutrients, so after the peony blossom, you can cut off residual flowers, use fertilizer, let peony rest, restore vitality, and, conducive to flower bud differentiation from June to August.

The time for applying fertilizer after flowering is about half a month after flowering. This time, it is May when the temperature is not very high. At this time, you can use some mature organic fertilizer, mix, some compound fertilizer, both to supplement energy, improve the quality of flower bud differentiation.

By June, the crucial period for flower bud differentiation has begun, but this is the hot season, so it is not appropriate to fertilize the roots, but you can spray some Monopotassium phosphate every half month to speed up the bud differentiation.

Three, good use of winter fertilizer

In the fall of September to October, the peony is about to enter the dormancy period, when we use overwintering fertilizer, so that the peony flower accumulation of nutrients and energy, for the overwintering and flowering next year ready.

This application of fertilizer, should be mainly decomposed manure, can raise the ground temperature, and can be mixed with some phosphorus and potassium fertilizer, improve the ability of cold peony flowers, for the next flowering storage,